The Kaplan Foundation is a foundation dedicated to the scholarship and preservation of the music of Gustav Mahler set up by businessman and amateur conductor Gilbert Kaplan.
The Kaplan Foundation has published facsimile editions of Mahler’s autograph manuscript of the Second Symphony, the Adagietto movement of the Fifth Symphony and the song, "Ich bin der Welt abhanden gekommen".
It has produced Mahler Plays Mahler, a recording using piano rolls that Mahler made of his own compositions. These rolls are the only documents that exist of Mahler as a performer.
The Foundation has also published Mahler Discography (together with editor Pèter Fülöp), a definitive guide to 2,774 recordings of Mahler’s music; Mahler’s Concerts, by Knud Martner, a compilation of the 323 known performances led by Mahler as a conductor or pianist; and The Mahler Album (editor Gilbert Kaplan), an award-winning illustrated biography containing all known photographs and a selection of drawings and sculptures of the composer.
Together with Universal Edition, the Foundation is co-publisher of two scores of Mahler’s Second Symphony: the New Critical Edition (editors Renate Stark-Voit and Gilbert Kaplan) and the Arrangement for Small Orchestra (by Gilbert Kaplan and Rob Mathes); and with C. F. Peters, co-publisher of the New Critical Edition of Mahler's Sixth Symphony.
The Kaplan Foundation is located in New York City.